Step 1Stir together brown sugar, flour, salt and milk in medium saucepan. Bring to boil over low heat. Cook and stir until mixture begins to thicken, about 15 to 20 minutes. Lightly beat eggs in small bowl or cup. Add little hot pudding to eggs, whisking to blend well. Add egg mixture to remaining hot pudding and mix well. Cook and stir until mixture is thick and smooth, 2 to 3 minutes. Stir in butter and vanilla.
Step 2Place about 2 heaping spoons of pudding in 1 1/2-quart shallow glass serving dish, then spread over bottom. Top with 15 vanilla wafers, slices from 2 bananas and a third of remaining pudding. Repeat layers twice. Cover and chill pudding 8 hours or overnight.
Step 3Whip cream, then spread on top of pudding. Garnish with additional vanilla wafers stuck vertically around edge of bowl to form scalloped edges, or crush wafers and sprinkle over top.